1. Field of the Invention
The present invention relates to an electron detection apparatus for detecting information contained in electrons emitted from a sample surface. More particularly, the invention relates to such an apparatus using a structure of a scanning tunnel microscope having a probe with an aperture.
2. Description of the Prior Art
ESCA (Electron Spectroscopy for Chemical Analysis) or XPS (X-ray Photoelectron Spectroscopy) has been used for surface analysis. In ESCA, while irradiating X-rays onto a sample, a minute area on the sample surface is subjected to sampling with an aperture or a slit of a small size. The minimum area detectable with the aperture or the slit would be 30 microns square at the most. If it is contemplated to further reduce the size of the detecting area, high intensity X-rays need to be irradiated onto the sample, which however can destroy the sample.